STAG2 and myelodysplastic syndrome: In GATA2-related MDS (GATA2-MDS), few studies reported a high prevalence of monosomy 7, der(1;7) [25, 26] and somatic mutations in genes including SETBP1, ASXL1, RUNX1 [8, 24, 28–30], while somatic STAG2 variants were rarely observed in patients with myeloid malignancy [8].